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Young Voices for the Planet DVD in our online store includes 8 films where students speak out and take action on climate change.

Exploratour - Life in the Solar System

Life on Earth obtains energy in many types of formats. The two main process are photosynthesis and respiration. Photosynthesis is the name of the process by which autotrophs (self-feeders) convert water, carbon dioxide, and solar energy into sugars and oxygen. Oxygen is a waste product of this activity. The photosynthetic activity of early bacteria helped build the oxygen content of Earth's atmosphere so that oxygen-dependent animals, including humans, could live.

The reverse of this process, used by heterotrophs (other-feeders) coverts sugars and oxygen into biological energy. Carbon dioxide and water are produced as waste products.

Respiration, unlike photosynthesis, takes advantage of a natural tendency of oxygen to combine with other molecules. When combining with other substances, oxygen tends to release large amounts of energy. Thus life forms which employ the process of respiration are taking advantage of the most efficient and energetic pathway nature provides to produce bioenergy on Earth.

Certain forms of bacteria can covert energy by breaking down exotic molecules without using photosnythesis or respiration, however. Likewise, life elsewhere in the solar system may rely on an energy conversion process which has yet to be discovered by human science. One way to search for life is to try and detect the waste products from life's activity. Read more about NASA's current attempts to search for life in the Exploratour on NASA's Exploration for Life at the bottom of this page.

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Shop Windows to the Universe Science Store!

Learn about Earth and space science, and have fun while doing it! The games section of our online store includes a climate change card game and the Traveling Nitrogen game!

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Traveling Nitrogen Classroom Activity Kit

Check out our online store - minerals, fossils, books, activities, jewelry, and household items!...more

ExploraTour - Looking at the World in a Different Light

Look at the bed below the body of the sleeping man. You can still see where he was lying down. The heat from his body warmed up the bed sheets which are now radiating infrared light toward your eyes....more

ExploraTour - Looking at the World in a Different Light

All warm objects (not just people) release infrared light. Warmer objects give off more infrared light. Very hot objects radiate other types of light as well. Click on the picture to see the infrared...more

ExploraTour - Looking at the World in a Different Light

What kinds of light can people see? Our eyes can see visible light. When it passes into our eyes different types of visible light create different sensations that we see as colors. ...more

ExploraTour - Looking at the World in a Different Light

Imagine you found a pair of special glasses that not only gave you telescopic vision but gave you the ability to see all forms of radiant energy. The universe in visible light contains all the familiar...more

ExploraTour - Looking at the World in a Different Light

This is a volcano on the island of Miyake in Japan. It has erupted, sending hot lava and ash into the air, a total of ten times. The time after one eruption until the next occurred was about twenty years...more

ExploraTour - Looking at the World in a Different Light

This is a picture of a galaxy in visible light. A galaxy is a large number of stars, some like our sun, some bigger, some smaller and all moving together through space. This galaxy is called Centaurus...more

ExploraTour - Looking at the World in a Different Light

This is a plant in Gary, Indiana where power is made. We use power to run things like television sets, radios, lights, and microwave ovens. The picture looks very strange because it was taken in infrared....more

Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part is sponsored in part through grants from federal agencies (NASA and NOAA), and partnerships with affiliated organizations, including the American Geophysical Union, the Howard Hughes Medical Institute, the Earth System Information Partnership, the American Meteorological Society, the National Center for Science Education, and TERC. The American Geophysical Union and the American Geosciences Institute are Windows to the Universe Founding Partners. NESTA welcomes new Institutional Affiliates in support of our ongoing programs, as well as collaborations on new projects. Contact NESTA for more information. NASA ESIP NCSE HHMI AGU AGI AMS NOAA